Ultrathin high-speed airfoil model capable of synchronously and dynamically measuring force and pressure in real time

Abstract

The invention belongs to the technical field of aerodynamic experimental measurement, and provides an ultrathin high-speed airfoil model capable of synchronously and dynamically measuring force and pressure in real time, which is characterized in that a balance fixing area is arranged in a model body, and the model body is sealed by a balance fixing area cover plate; the microbalance is fixedly installed in a balance fixing area in the model body. The model force measuring section is connected with the microbalance, and a gap of 1-2mm is reserved between the model force measuring section and the model body and is used for isolating additional torque of a dynamic mechanism; the force measuring section cover plate covers the model force measuring section to form a pneumatic smooth surface; the pressure measuring area cover plate and the model body jointly form a pressure measuring structure, and the pressure measuring area is far away from the boundary of the tunnel wall of the wind tunnel test section; according to the invention, the aerodynamic change caused by the air flow on the model surface sensed by the force measuring section of the airfoil model can be truly reflected, the additional accessory torque is not contained, and the function of synchronously and accurately measuring the aerodynamic parameters of the high-speed airfoil model in real time is realized.

Description

Technical Field

[0001] This invention belongs to the field of aerodynamic experimental measurement technology, specifically a synchronous real-time dynamic force and pressure measurement ultrathin high-speed airfoil model. Background Technology

[0002] Wind tunnel airfoil models are commonly used research objects in scientific research and production, especially in the field of aircraft design. Wind tunnel testing is an effective means of studying and verifying the aerodynamic characteristics of new and optimized airfoils.

[0003] Currently, in most airfoil experiments, especially those conducted in high-speed wind tunnels, the airfoil model used is installed on the rotating window of the wind tunnel test section. The airfoil model spans both sides of the airfoil test section and is fixed in the outer chamber of the test section by model lugs. After obtaining the pressure distribution on the model surface through pressure measuring equipment connected to the pressure measuring pipeline, the lift of the airfoil is obtained. By installing a tail rake at a certain distance downstream of the airfoil model, the flow region of the longitudinal section of the airfoil wake is completely captured without generating additional interference. The drag and moment characteristics of the airfoil model are obtained by integrating the surface pressure.

[0004] Measuring the aerodynamic forces of a model using a balance is a direct measurement method. The balance is placed inside the model, and as the model's attitude changes, the balance can measure the lift, drag, and torque of the model in real time, directly, and accurately.

[0005] Currently, the structure of installing a balance inside the airfoil is mainly used for low-speed airfoils. High-speed airfoils, due to the size of the test section and the requirements for wind tunnel obstruction, have smaller airfoil thicknesses, making it difficult to place a force balance inside the model. Low-speed airfoil tests have larger test section cross-sectional areas and greater airfoil thicknesses. Furthermore, low-speed airfoils generally use a metal main frame with wood or composite materials filling the middle to reduce airfoil weight, and metal skin to maintain the airfoil profile. This structure allows for the placement of the balance in the center of the model without compromising the airfoil structure. However, high-speed airfoil tests have smaller wind tunnel test section cross-sectional areas, and high-speed model wind tunnel tests have strict requirements for test section obstruction, resulting in smaller thicknesses in existing high-speed airfoil test models. Especially for airfoils with large camber, the thickness is sometimes only about 13mm, making it extremely difficult to use a conventional force balance and place it inside the model cavity.

[0006] Currently, aerodynamic characteristic tests on high-speed airfoil models primarily employ surface pressure measurement. This involves connecting a high-precision pressure scanning valve to the surface pressure measurement port to obtain the pressure distribution at localized locations on the airfoil surface, and then integrating the pressure to obtain the airfoil's lift. Alternatively, force measurement is achieved by mounting a force balance outside the airfoil test section. A pair of force balances are symmetrically installed on the airfoil lugs within the wind tunnel test chamber and connected to obtain the airfoil's aerodynamic forces and moments. However, this external balance method can lead to overestimation of the forces and moments sensed by the balances. It cannot completely eliminate the additional moment caused by the contact between the wind tunnel test section sidewall and the model. Furthermore, even slight differences in the synchronicity of the two balances can introduce interference factors into the measurement results of the micro-balance. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides an ultrathin high-speed airfoil model with synchronous real-time dynamic force and pressure measurement. This model enables force measurement of the high-speed airfoil model, allowing for synchronous measurement of force and pressure, mutual verification and reference. Furthermore, it allows for the installation of a micro-balance inside the airfoil to avoid excessive interference from additional torque, thus resolving the problems mentioned in the background art.

[0008] A synchronous real-time dynamic force and pressure measurement model for ultrathin high-speed airfoils includes:

[0009] The model body has a balance fixing area inside, which is sealed by a balance fixing area cover plate;

[0010] A micro balance is fixedly installed in the balance fixing area inside the model body;

[0011] The model force measuring section is connected to the micro balance and has a 1-2mm gap between it and the model body to isolate the additional torque of the dynamic mechanism.

[0012] A force measuring section cover plate covers the force measuring section of the model, forming a pneumatically smooth surface;

[0013] The pressure measurement zone cover plate, together with the model body, constitutes the pressure measurement structure, and its pressure measurement area is far away from the boundary of the wind tunnel test section wall.

[0014] Preferably, the microbalance is a high-precision strain gauge balance used to measure lift, drag and pitch torque, and its measurement data is not affected by the rolling torque caused by the dynamic motion of the model.

[0015] Preferably, the gap between the model force measurement section and the model body is designed to ensure that the aerodynamic measurement only reflects the aerodynamic changes of the flow on the model surface, avoiding interference from additional torque.

[0016] Preferably, multiple sets of dynamic pressure sensors are densely arranged along the airfoil surface on the right side of the model body to capture the flow separation, shock wave oscillation, and fine flow characteristics of the airfoil surface.

[0017] Preferably, the distance between the pressure measuring area of ​​the pressure measuring zone cover plate and the spanwise boundary of the airfoil meets the requirement of minimizing wind tunnel wall interference.

[0018] Preferably, the fixed end of the microbalance is rigidly connected to the model body, and the free end is fixedly connected to the force measuring section of the model by screws.

[0019] Preferably, the microbalance measures the lift, drag, and pitching moment of the force measuring section of the model in real time;

[0020] The dynamic pressure sensor collects pressure distribution and pulsation signals on the airfoil surface;

[0021] By operating pressure and force measurement functions simultaneously, cross-checking data, and jointly analyzing force and pressure measurement data, wind tunnel wall interference and dynamic motion errors can be corrected.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention can accurately reflect the aerodynamic changes caused by the gas flow on the model surface as perceived by the force measurement section of the airfoil model, without the need for additional attachment torques. It realizes the function of synchronous, real-time, and accurate measurement of the aerodynamic parameters of high-speed airfoil models, enabling synchronous real-time force and pressure measurement of ultra-thin high-speed airfoil models, reducing interference factors, and achieving the goal of accurate measurement. Attached Figure Description

[0024] Figure 1 This is a front view of the micro-force and pressure measuring airfoil model of the present invention;

[0025] Figure 2 This is a top view of the dynamic model of the high-speed micro-force and pressure measuring airfoil of the present invention;

[0026] Figure 3 This is a cross-sectional view of the pressure measuring hole arrangement in the pressure measuring area of ​​the model body of the present invention.

[0027] In the picture:

[0028] 1. Model body; 2. Balance fixing area cover plate; 3. Model force measuring section; 4. Force measuring section cover plate; 5. Pressure measuring area cover plate; 6. Micro balance; 7. Screws. Detailed Implementation

[0029] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0030] As attached Figure 1 To be continued Figure 3 As shown:

[0031] Example: This invention provides an ultrathin high-speed airfoil model for synchronous real-time dynamic force and pressure measurement, comprising: a balance fixing area set inside the model body 1 and sealed by a balance fixing area cover plate 2; a micro balance 6, fixedly installed inside the balance fixing area inside the model body 1; a model force measuring section 3 connected to the micro balance 6, with a 1-2mm gap between it and the model body 1 to isolate the additional torque of the dynamic mechanism; a force measuring section cover plate 4 covering the model force measuring section 3 to form an aerodynamically smooth surface; and a pressure measuring area cover plate 5 together with the model body 1 to form a pressure measuring structure, with its pressure measuring area far away from the boundary of the wind tunnel test section wall.

[0032] The microbalance 6 is a high-precision strain gauge balance used to measure lift, drag, and pitching moment. Its measurement data is not affected by the rolling moment caused by the dynamic motion of the model. It can truly reflect the aerodynamic changes caused by the gas flow on the model surface as felt by the force measurement section 3 of the model. It does not contain any additional accessory torques and truly realizes the accurate force and pressure measurement function of the airfoil model.

[0033] The gap between the model force measuring section 3 and the model body 1 is designed to ensure that the aerodynamic measurement only reflects the aerodynamic changes of the flow on the model surface, avoiding interference from additional torque. After the microbalance 6 is installed and fixed on the model body 1, the model force measuring section 3 moves with the movement of the model body 1. The rolling torque caused by the dynamic mechanism itself on the airfoil is not included in the measurement range of the microbalance 6 under this structure, greatly reducing the torque component of the balance.

[0034] Multiple sets of dynamic pressure sensors are densely arranged along the airfoil surface on the right side of the model body 1 to capture the flow separation, shock wave oscillation and fine flow characteristics of the airfoil surface.

[0035] The distance between the pressure measurement area of ​​the pressure measurement zone cover plate 5 and the spanwise boundary of the airfoil meets the requirement of minimizing wind tunnel wall interference.

[0036] The fixed end of the microbalance 6 is rigidly connected to the model body 1, and the free end is fixedly connected to the force measuring section 3 of the model by screws 7.

[0037] The microbalance 6 measures the lift, drag, and pitching moment of the force measurement section 3 of the model in real time; the dynamic pressure sensor collects the pressure distribution and pulsation signal on the airfoil surface; through the synchronous operation of pressure measurement and force measurement functions, the data are cross-verified, and the force and pressure measurement data are jointly analyzed to correct wind tunnel wall interference and dynamic motion errors.

[0038] As can be seen from the above, the high-speed airfoil model with built-in microbalance 6 in this invention can effectively realize the force measurement function of the high-speed airfoil model, and the microbalance 6 can be installed inside the airfoil to avoid the problem of excessive interference from additional torque. At the same time, the high-speed airfoil model in this invention can realize the simultaneous measurement of force and pressure, which can be mutually verified and referenced.

[0039] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible without substantially departing from the novel teachings and advantages of the subject matter described in this application. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the invention is not limited to the particular embodiments but extends to a variety of modifications that still fall within the scope of the appended claims.

[0040] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0041] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A synchronous real-time dynamic force and pressure measurement ultrathin high-speed airfoil model, characterized in that, include: The model body has a balance fixing area inside, which is sealed by a balance fixing area cover plate; A micro balance is fixedly installed in the balance fixing area inside the model body; The model force measuring section is connected to the micro balance and has a 1-2mm gap between it and the model body to isolate the additional torque of the dynamic mechanism. A force measuring section cover plate covers the force measuring section of the model, forming a pneumatically smooth surface; The pressure measurement zone cover plate, together with the model body, constitutes the pressure measurement structure, and its pressure measurement area is far away from the boundary of the wind tunnel test section wall.

2. The ultrathin high-speed airfoil model with synchronous real-time dynamic force and pressure measurement as described in claim 1, characterized in that: The microbalance is a high-precision strain gauge balance used to measure lift, drag, and pitching moment, and its measurement data is not affected by the rolling moment caused by the dynamic motion of the model.

3. The ultrathin high-speed airfoil model with synchronous real-time dynamic force and pressure measurement as described in claim 1, characterized in that: The gap between the force measurement section of the model and the model body is designed to ensure that the aerodynamic measurement only reflects the aerodynamic changes of the flow on the model surface, avoiding interference from additional torque.

4. The ultrathin high-speed airfoil model with synchronous real-time dynamic force and pressure measurement as described in claim 1, characterized in that: Multiple sets of dynamic pressure sensors are densely arranged along the airfoil surface on the right side of the model body to capture the flow separation, shock wave oscillation, and fine flow characteristics of the airfoil surface.

5. The ultrathin high-speed airfoil model with synchronous real-time dynamic force and pressure measurement as described in claim 1, characterized in that: The distance between the pressure measurement area of ​​the pressure measurement zone cover plate and the spanwise boundary of the airfoil meets the requirement of minimizing wind tunnel wall interference.

6. The ultrathin high-speed airfoil model with synchronous real-time dynamic force and pressure measurement as described in claim 1, characterized in that: The fixed end of the microbalance is rigidly connected to the model body, and the free end is fixedly connected to the force measuring section of the model by screws.

7. The ultrathin high-speed airfoil model with synchronous real-time dynamic force and pressure measurement as described in claim 1, characterized in that: The microbalance measures the lift, drag, and pitching moment of the force measurement section of the model in real time. The dynamic pressure sensor collects pressure distribution and pulsation signals on the airfoil surface; By operating pressure and force measurement functions simultaneously, cross-checking data, and jointly analyzing force and pressure measurement data, wind tunnel wall interference and dynamic motion errors can be corrected.

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